Rotary kiln

摘要

A rotary kiln includes a cylindrical kiln body supported for rotation about a central axis inclined with respect to a horizontal plane, a cylindrical combustion chamber formed inside the kiln body and extending along the central axis, and a plurality of cylindrical calcination chambers formed inside the kiln body so as to lie parallel with and surround the combustion chamber. The combustion chamber has an outlet at its lower end from which residue produced by combustion of fuel inside the combustion chamber drops for further combustion and/or discharge. Each calcination chamber has an inlet at its elevated end for receiving a supply of raw material to be calcined inside the calcination chamber, an opening at its lowermost end communicating with the outlet of the combustion chamber for receiving high-temperature combustion gases from the interior of the combustion chamber, and an outlet adjacent its lowermost end from which the calcined raw material drops for further calcination and/or collection without contacting the residue from the combustion chamber. Calcination in the calcination chambers is effected by heat transmitted from the combustion chamber through the kiln body and by heat given off by the high-temperature gases received from the combustion chamber.